Valve tip construction



March 25, 1958 VALVE TIP CONSTRUCTION Filed Dec. 16, 1954 F25 l c /J 26; iz/ 26 i//c ,4

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Unite States Patent VALVE Ti? CONSTRUCTION Herbert H. Engemann, Cleveland Heights, Ohio Application December 16, 1954, Serial No. 47 5,635

17 Claims. (Cl. 12S- 188) This invention relates to improvements ina v-alve assembly construction and more particularly to a wear tip construction for a valve stem.

The valve stem tip on an internal combustion engine valve is subjected to considerable wear at its contact with the rocker arm, tappet or other valve actuating member during the operation of the engine. The relative movement, such as a sliding or rubbing movement, at this contact causes wear; this wear is especially noticeable when a pivoted oscillating rocker arm is being used to actuate a reciprocating valve. As wear occurs, clearances increase, noise increases as the relatively moving members snap into and out of the worn groove, and side thrust on the valve guide increases as new forces are created by the worn construction.

Several solutions to this wear problem have been considered but have not been found satisfactory. First, the valve stem tip is hardened or tempered by suitable heat treatment. However, some valve stems are not hardenable. Second, -a hard material is welded or brazed to the valve stern tip. This process not only is expensive but also often complicates heat treatment of the valve stem. Valves having either of these rst two mentioned constructions may soon become worn or sculfed to the extent that repair becomes advisable; this repair is expensive since the valves must be removed from the engine and the valves themselves must be reconditioned. Third, a cup-shaped removable and hardened cap may be telescopically mounted over the valve stem tip. While this construction may be less expensive than the rst two mentioned constructions, it has the disadvantage of requiring extra valve stem length to provide suicient side engagement to retain the cap on the valve stern during engine operation. The present invention not only eliminates all of the above-mentioned disadvantages and many others but also includes features not found in these constructions.

One of the objects of the present invention is to provide a low-cost and easily replaceable wear surface for the end of a valve stem.

Another object of the present invention is to provide la, wear surface on a wear member of simple shape, such as a disk, so that hard materials, such as tungsten carbide, stellite, etc., can be used, which materials would be difiicult and expensive to shape into a suitable cup-shape cap or to weld or braze to the end of a valve stem.

Another object of the present invention is to provide a reversible Wear member for a valve stem with said member having reversible wear surfaces thereon to double the wear life.

Another object is to provide a retaining means for a wear member Without adding additional parts to but by only slightly modifying conventional valve assembly construction.

Another object of the present invention is to provide a Wear member having a Wear surface which can be made of extremely hard material.

Another object of the present invention is to provide ICC a retaining means for a` wear member on a valve stem (l) to permit free rotation or iloat of the wear member relative to the valve stem to equalize wear and increase wear life, (2) to prevent or to permit axial removal of the wear member from the valve stem without otherwise disassembling the unit, and/or (3) to clamp the wear member against the valve stem to prevent rotation with respect thereto and removal therefrom.

Another object of the present invention is to provide a wear member with a hard wear surface substantially harder than the valve stem to which it is adapted to be attached so that the hard surface will resist wear while the valve stem will be tough enough to have long life.

Another object of the present invention is to provide in a single compact unit a combined valve stem wear cap and valve spring retainer construction providing both functions, being inexpensive to manufacture by altering conventional valve assembly construction, providing maximum spring length for a given valve length, and providing minimum valve stern protrusion above the valve spring retainer.

Other features in this invention reside in the arrangement and design of the parts for carrying out their appropriate functions.

Other objects and advantages of this invention will be apparent from the accompanying drawings and description and the essential features will be set forth in the appended claims.

In the drawings,

Fig. 1 is a longitudinal sectional View taken along the line 1-1 of Fig. 2 of an internal combustion engine poppet valve assembly construction having the present invention incorporated therein;

Fig. 2 is a plan view of assembly shown in Fig. 1 with rocker arm removed; while Figs. 3 and 4 are enlarged, fragmentary views of the upper half of Fig. l but illustrating a second and third form of wear assembly construction.

Before the valve assembly construction herein illustrated is specifically described, it is to be understood that the invention here involved is not limited to the structural details or arrangement of parts here shown since constructions embodying the present invention may take various forms. It also is to be understood that the phraseology or terminology herein employed is for purposes of description and not of limitation since the scope of the present invention is denoted by the appended claims.

Those familiar with this art will recognize that my invention may take various forms and may be applied in many ways, but I have chosen to illustrate the same in connection with a replaceable wear surface construction for an internal combustion engine valve stem tip of known type.

The conventional internal combustion engine construction forms a part of the Fig. 1 illustration. The conventional internal combustion engine housing l0 has a valve port 10a, either of the exhaust or inlet type, adapted to be opened and closed by endwise movement of valve head 11a on poppet valve 11. The valve is opened by having a generally axial force exerted downwardly on the top of the valve stem by valve actuating member or rocker arm 13; Valve 11 is returned to its closed position illustrated in Fig. 1 by the force of valve spring 12 upon removal of this valve opening force.

Any suitable spring retainer means may be used for abutting against one end of the valve spring and operatively connecting it to the valve stem. In the present construction, this means includes an annular spring retainer member 14 telescopically mounted over valve stem 1lb remote from valve head 11a with this member 14 being operatively connected to the Valve stem, in a manner to be described in more detail hereinafter, by means for Apreventing substantial 'relative movement away from Athe valve head. This spring retainer meansmay if desired take the form of a valve rotator construction, operable in response to changes in the force of spring 12 and hav- -ing relatively axially movable members. Y

Three-different forms Vof wear assembly construction are"illustrated. These include wear members ,15, 25 and 35 `in Figs. l, 3 and 4 respectively. Each wear kmember is of generally disk shape having generally parallel opposite surfaces, designated by the reference Vnumeral suffixes a and b, Vadapted to be located between and to coact respectively with valve actuating member 13 and'valve stem tip or squared end 11C. Each disk is 4approximately the vsame diameter as Vthe valve stem and "is detachably mounted .in generally coaxially yor concentrically aligned relationship with the valve stem 11b. Wear member V15fhas an annular and cylindrical surface :e with Yan outwardly extending integral, an nular ange Y15d at the end adjacentV the valve stem; wear A'1:uen1be1'25 has 'an annular 'peripheral 'surface 25e forming a convex curve in "longitudinal section; and wear Ymember` "has 'an annular or cylindrical peripheral Vsur- 'face 35C throughout its whole length.

Each of these wear members is detachably assembled in proper relationship with valve stem tip llc by a wear member retainer means. Each retainer means ,is vformed `from surrounding annular surfaces taking the form ot a sleeve, at least one segment of, or agroup of segments o'f an .annular element, here shown asbeing twoin number in Fig. 2/but suitably composed .of any .desired number.

groups are of slightly different construction .andare here designated as retainer segmentsor keys 16, 26 and 36 in Figs. l, 3 and .4 respectively. However, any suitably shaped split key construction, collet with .separate `and 'independent retainer segments or Ainterconnected `(such as integral) retainer segments, or .other keying means and any suitable coacting valve :stem `shape may 4be used. In Figs. 1, 3 .and 4, each of these segments is :independentof its associated wear member and the opposite parallel surfaces thereon. Each .group of segments :and its associated wear member forms an embracing andrcoact- `ing construction for detachable assembly. 'Ihe term embracing is intended to include not only the preferred construction herein shown with the bore .of the segments surrounding the periphery of their associated wear member, but also ,the alternative construction with `the` en- .circlement yof the parts reversed by :having a-wear member of -cap form having a depending .annular skirt tonn- Ving a bore surrounding coacting surfaces on the periphery of Vits associated group of zsegments.

.Acommon assembling mea-ns is :provided for retaining both the-wear ,member and spring ,retainer ymeans in assembled position on valve :stem 11b.. Ea'chof the three illustrated for-ms of invention is vbasically the same in this regard. Each has coacting tapers 14t in 'the bore of `the annular Vspring ,retainer member .14 and .tapers 1.6t, 261? lor 361* fon the periphery of its 'associated `segments. The bore formed by each `group of ,segments has Vat least one inwardly directed, shoulder or projection 16p, 26p or 36p `on `each segment thereof coacting with fa peripheral groove 11d on the valve stem to fonn an interlockable construction. But it should be realized that the projections `and grooves can be reversed fon the parts and still obtain the same function. In .each illustrated .form vof the invention, the valve spring V`biases these coacting tapers together andurges'the v:associated group `of segments iirmly A.against .the associated Ivalve stem Vso that the .shoulder projectionsare 'tor-ced into and rcoact'with their :associated groove Ito prevent relative movement-fof the assembly `axia'llyalong the associated `valve stem by the valve spring. lThe coacting tapers and spring i-n each term 4of the invention urge the associated group of segments radially "inwardly into wear mem- The keys or retainer segments in each vofthe three A -b ber retaining relationship by embracing both the associated `valve stem -and wear member.

The illustrated forms of the invention have many advantages.

First, the contacting fit between or the diametrical dimensions of the embracing surfaces on each wear member and its associated retainer segments may be altered to give different characteristics to the construction even though the general form of the component parts remains as illustrated and each group of segments always iirmly engages its associated valve stem periphery.

The dimensions of the embracing surfaces may be chosen so that diametrical dimensional clearance exists between these surfaces to permit rotational freedom of the associated wear member for rotation or float about an axis generally coaxial with the longitudinal axis of the valve stem. In each of the three forms of the invention, the wear `member peripheral surfaces and its surrounding retainer .segment bore surfaces are annular in shape to form concentric, .circumferentially disposed surfaces with a sliding tit therebetween to permit relative `rotation :of the wear member. member .can rotate `or float under the inuence ot the forces ,exerted thereon by ,coaction between valve 11 and its actuating ,member 13 .so that this freedom of movement will equalize the wear and increase the life of the wearmember. Y

This wear member retainer construction permitting free rotation may either lock against or permit axial removal of the Wear member from Vthe assembly. Lock means is provided in Figs. 1 and `it to prevent axial removal of the associated wear members from the assemblies. This lock means is provided by having groove or recess 16g or 26g in Figs. 1 and 3 respectively formed in the wear ,member embracing bore of the retainer segment ,group 16 or 26 for rotatably housing flange 15d in Fig. l or convex peripheral curved surface 25e in Fig. 3 with thefradially inwardly projecting shoulder forming the upper end of each groove or recess preventing axial removal of Vits wear member from the respective assem- V-bly. In Fig. 4, wear member `35 may be axially re- .moved from .the assembly, turned upside down and reversed in position, lor originally installed without first loosening segments 36 or disassembling them from as- .sembled position inFig. 4. However, this axial removal :is normally prevented by the contact pressure of rthe -valve actuating member ,13 normally pressing wear .member .35 down against the valve stem `tip 11c..during engine operation.

Y vIn each form of the invention, the ywear member may be .clamped to 4the valve stem kto prevent not only axial `rernoval'therefrom but also relative rotation with respect thereto by providing a diametrical dimensional interference or friction tit between these embracing surfaces 'in assembled position. The group of segments then act as a vclamping .collet to tirmly clamp the wear member to the valve stem tip. Of course, any suitable complexrmentary shape .on the .embracing surfaces of the vretainer segments and :associated wear member may be used for lclamping since concentricity .or generally annular shape lis no longer required to permit rotation.

Any .of these aforementioned ts and locks are A,possible with these constmctionssince spring 12 and coacting tapers .-14t and 16t, v26t `or 36x rmly press the -bore of their respective retainer segments against the associated cylindrical valve .stem periphery to `maintain accurately the diametrical dimensions between thedistal or upper endslof the retainer segments embracing the associated V)wear member.

'These illustrated forms Aof the invention also Vhave other characteristics independent of the diametrical clearance lbetween `the embracing surfaces.

Second, the wear member may-be made of a diierent hardness than the valve stem vso that yeach Awill 'have Hence, the wear asa'assi maximum wear life. The hardness ofthe wear member will resist the wear caused by the relative sliding action of the valve operating member 13 while the toughness of the valve stem will resist premature failure caused by stress concentration at valve stem peripheral groove 11d. If no separate wear member were used and the valve stem tip were hardened sufficiently to resist wear, it would prematurely fail at the peripheral groove under the endless repetition of stresses to which a poppet valve is subjected.

Third, wear members 25 and 35 in Figs. 3 and 4 respectively are reversible in their retainer means to give a double length wear life. Since each is symmetrical about a transverse central plane, it can be reversed to present either of its two, opposite, parallel wear surfaces (25a, 25h or 35a, 35b) to contacting relationship with the valve actuating member 13. Since both wear members 25 and 35 are also bisymmetrical in form and have an annular peripheral shape, they not only are reversible in their retainer means but are also adapted to rotate relative thereto.

Fourth, a maximum spring length in Fig. l is obtained for a given valve length in each form of the invention since the assembled parts are all located in approximately coplanar relationship in a transverse plane at the valve stem tip remote from the valve head and since the valve spring retainer means and the wear member retainer means have many common, coacting parts providing functions for both means. This coplanar relationship is clearly shown in Fig. l; slight modification of the coasting tapers in Figs. 3 and 4 will form basically the same construction. desirable since it keeps the overall valve length and overall engine dimensions down to a minimum for proper tit into an automobile, for example.

Fifth, the top surface of each segment is located below the top wear surface (a, 25a or 35a) of its associated wear member so that valve actuator 13 may coact with this wear surface to actuate the valve and be free to slide across this wear surface Without interference with the retainer segments.

Sixth, the construction is inexpensive to manufacture and inexpensive to service or repair. The combined valve stem wear tip and Valve spring retainer construction provides in a single unit a dual function. Also, only a slight modification of the segments on a valve spring retainer is required to form the wear member retainer construction. Each of the illustrated wear members is an easily manufactured, simple shape of a generally disk form; each may be wholly formed of or have a surface formed thereon of any suitable hard material, such as tungsten carbide, stellite, etc. Also, when repair is required, only the wear member (the only wearable part) need be replaced. The construction permits easy assembly and disassembly of the wear member on the valve stem tip without welding, brazing or other heating opera tions. The repair man need only depress the annular valve spring retainer member 14 a slight amount against the bias of the valve spring 12 to release the retainer segments sufliciently from the coacting taper bore 141? to permit removal of the worn wear member and installation of a new one.

Various changes in details and arrangement of parts can be made by one skilled in the art without departing from either the spirit of this invention or the scope of the appended claims.

What I claim is:

1.` In a combined valve stern wear tip and valve spring `retainer structure, a spring retainer means forabutting against one end of a valve spring, a wear member, wear member retainer means forming with said wear member an embracing connection therebetween for detachably assembling said wear member to the tip of said valve stem remote from the valve head, and assembling means @Operating with the bias of said valve spring for re- This ratio of spring and valve length is taining said wear member retainer means and said'spring retainer means in assembled position with said valve and against axial relative substantial movement in at least one direction with respect to said valve, said wear member being symmetrical about a transverse central plane so that said member may be reversed to present either of two opposite wear surfaces.

2. In a combined valve stem wear tip and valve spring retainer, a spring retainer means for abutting against one end of a valve spring, a wear member, wear member retainer means for detachably assembling said wear member to the tip of said valve stem remote from the valve head, and assembling means cooperating with the bias of said valve spring for retaining said Wear member retainer means and said spring retainer means in assembled position with said valve and against axial relative substantial movement in at least one direction with respect to said valve, said assembling means including on said valve stem and at least one of said retainer means a coacting projection and groove interlockable construction for preventing relative axial movement of both said retainer means relative to said valve stem, said wear member being substantially harder than said valve stem to resist wear thereon while the softness of said valve stem resists breakage at said interlockable construction.

3. In a combined valve stern wear tip and valve spring retainer, a spring retainer means for abutting against one end of a valve spring, a wear member, wear member retainer means for detachably assembling said wear member to the tip of said valve stem remote from the valve head, and means cooperating with the bias of said valve spring for retaining said wear member retainer means and said spring retainer means 'in assembled position with said valve stem and against axial relative substantial movement in at least one direction with respect of said valve stem, said wear member retainer means and said ear member having thereon concentric circumferentially disposed coacting surfaces forming a bore in one embracing a periphery on the other with the diametrical clearance therebetween to permit relative rotation thereof.

4. In the construction in claim 3, wherein the peripheral surface is on said Wear member and has a generally cylindrical surface throughout its whole length for permitting axial removal of said wear member from said bore and for permitting relative rotation of said wear member within said bore but with said axial removal normally prevented by having the actuating member for said valve normally pressing the wear member against the valve Stem.

5. In the construction in claim 3,1ock means to prevent axial removal of said wear member from said valve stem.

6. In the construction in claim 5, wherein said wear member retainer means includes rsegments of an annular element, and wherein said lock means includes radially projecting shoulders on said segments, each shoulder having its surface located most remote from the valve head being located below the wear surface of said wear member most remote from the valve so that the valve actuator may coact therewith without interference.

7. In the construction in claim 3, lock means to prevent axial removal of said wear member from said valve stem, said wear member being bisymmetrical in form whereby said Wear member may be reversed to present either of two wear surfaces.

8. In the construction in claim 3, wherein the peripheral surface is on said wear member and has a generally convex surve in longitudinal section, said bore having a recess therein to rotatably house said convex curve and to prevent axial removal of said wear member from said valve stern.

9. In the construction in claim 3, wherein the peripheral surface is on said wear member and has a generally cylindrical surface with an outwardly extending flange near one end, said bore having a recess therein to rotataananas 1 c 7 bly house said ilange and to prevent axial removal :of said wear member from said valve stem.

10. In a combined valve stemwear tip .andvalvespring retainer, a spring retainer means for abutting `against `one end 4of a valve spring, a wear member, wear member 'retainer means comprising segments of an .annular element forming with said wear member .an vembracing connection having a irictional lit therebetween of the collet type for detachably clamping .said-wear member to the tip of said valve stern remote from rthe valve head Vagainst axial and rotational movement relative thereto, and means cooperating with the bias :of vsaid valve spring Afor retaining said wear member retainer means and said spring retainer means in assembled vposition with said Vvalvestem and against axial relative substantial movement in at least one direction with respect to `said valve stem.

11. In `the construction in claim l0, wherein the snriace of said wear member at said embracing connection .has a generally cylindrical surface Athroughout its whole length.

12. In the construction in claim l0, wherein the surface of said wear member at said `enibraci'ng connection has a generally convex curve in longitudinal section.

13. In `the .construction in ,c1aim,l.0, wherein the surface of said wear member at said embracing vconnection Yhas a generally cylindrical surface vwith an outwardly extending flange.

14. In a combined valve stem wear .tip and valve spring retainer structure, a spring retainer means for abutting against one end of a valve spring, a wearmember, wear member retainer means forming with said =wear member an embracing connection therebetween for detachably assembling said wear member to the tip `.of said valve stern remote from the valve head, and assembling means cooperating with the bias of said valve spring for retaining said wear member retainer means and said spring retainer means in assembled position with said valve and against axial relative substantial movement `in `at least one direction with respect `to said valve, -said wear member being conned axially wholly on the side of i" said valve stem tip remote from said valve head, whereby the lateral dimension of said structure is 'minimized 15. In a combined valve stem wear tip and vailve spring retainer structure, a spring retainer means for abutting against one end of a valve spring, a wear member, wear member retainer means forming with `said wear member -an embracing connection therebetween for detachably assembling said wear member to the vtip of Said valve stem remote from the valve head, and assembling means cooperating with the bias of said valve spring for retaining Asaid wear member retainermeans and said spring re- -taxner means Iin assembled rposition withsaid valve `and against V,axialrelative substantial movement in ,atleast one :direct-ion with respect to said valve, said wear mem ber being a =ilat disc' .arranged transversely 4tofthe valve stemaxis. l.

16. In a combined valve .stern wear tip and valve spring Vretainer structure, `a spring retainer means for abutting against one end .of a Yvalve spring, .a wear member, wear member retainer means forming with said wear member v an embracing `connection'therebetween for detachably assembling said wear member to kthetip of said valve stem remote from the valve head, and :assembling means cooperating with the bias of said'valve .spring for retaining said wear member retainermeans and ,said spring'retainer means in assembled position with said valve andagainst ,axial relativey substantial movement sin at least one direction with respect to said valve, `:said wear member and said. retainer means having coacting surface means per mining axial removal of vsaid -vveartnernber without disturbing said retainer means.

17. UIn a combined valve stem wear tip `and valve ,spring retainer structure, a spring retainer means for abutting against one end of `a valve spring, aiwear member, wear Ymember retainer means forming with said wear Imember an embracing connection therebetween for detachably assembling said wear 4member to the-tip -oisaid valve .Stem remote from the valve head, and means cooperating with the bias of saidvalve `spring f orretaining said wear member retainermeans and said-springrretainer means in as- -sembled .position with .said valve stemand against axial relative substantial movement in atifleast :one .direction with respect of said lvalvestem, said wear member retainer means .and .said wear member having thereon concentric circumferentially disposed enacting surfaces forming a boreY in one embracing a periphery on the other with the wear member having a generally cylindrical sur- Y face throughout its Awhole length #for permitting axial .re-

moval of ,said nwear member :from-said retainer means but wit-h .saidy axial :removal normally. prevented :by having the actuating member for said vaivenormally pressing the wear .member into assembledposition.v

, References Citedin the .tile .of this patent UNITED STATES :PATENTS 

